Train-controlling system



Se im/l0, 1929. NIXQN 1,727,407

I Y TRAIN CONTROLLING SYSTEM Filed Mar ch 17, 1926 s Sheets-Sheet 1 FICtI- W1 TNESSES IN V EN TOR:

W a fi /w I I ATTORNEYS.

. Sept. 10, 1929. r-u or-| 11,727,407

TRAIN CONTROLLING SYSTEM Fil ed March '17; 1926 s sheets-sum 2 FIG: I.

IVI TNESSES IN VEN TOR: 9% 45mm. 97 Frederick/(Jfixon,

i 99 BY 9 4 a W 4 d0 95 ATTORNEYS.

Sept. 10, 1929. F. A. NIXON 1,727,407

TRAIN CONTROLLI NG SYSTEM WITNESSES INVENTOR- fiederick/ijfi'xon,

. BY W 4. MO 4 rom/53's.

Patented Sept. 10, 1929.

FREDERICK A. NIXON, OF EAS'ION, -PENNSYLVANIA'.

TRAIN- CONTROLLING SYSTEM. I

Application filed March 17, 1926. Serial No. 95,196.

This invention relates to electrically operated train controlling systems of the type embodying a conductor running contiguous to the track rails and divided into sections corresponding to block lengths.

More specifically this application is directed to the disclosure of my priorbut now abandoned-case filed the 4th 'day of August, 1922, under Serial Number 579,556, and it has for an object to provide an improved train controlling system which is characterized by the provision of means in each block for generating a pseudo-alternating current; or, more correctly What is termed a reversing pulsating current for impressing the current upon the conductor at varying frequencies: and a locomotive equipment for coordination with the throttle and air brakes of a train and responsive to such pseudo-alternating currentand frequency variations therein-to effect control of the speed of said train in any block with respect to that of a preceding or following train and to effect a complete stop of any train, without requiring the attention of the engineer andin a mannerentirely independent of his control.

In addition to the foregoing this invention comprehends improvements in the details of construction and arrangement of the correlated parts of what I now regard as the pre ferred embodiment of my invention from among many other possible forms and arrangements thereof, within the spirit of said invention, and which is hereinafter set forth and particularly pointed out in the appended claims.

In the accompanying drawings: 7

Figure I, is a diagrammatic view in plan of three block sections embodying my improved train controlling system, and illustrating the relative positions of corresponding parts in the respective block sections with their electrical connections to the track rails and conductor.

Figure 11, is a view in front elevation of a commutator forming part of a frequency controller or current converter used in connection with the present invention.

Figure III, is a view of the commutator and correlated parts in longitudinal section.

Figure IV, is a diagrammatic view illustrating the elements and their connections I lVith reference to Figure I of the draw- 2 ings, 10 indicates the track rails and 11 a conductor, located between said rails and running in contiguous relation thereto throughout the length of the track, said conductor being divided into live sections 12 located between thesections of a blocksignaling system, and subdivided into stopping sections 13, one of which is located between each adjacent end of anadjoining pair of live sections 12 and only of sufficient length to stop a train running at caution speed. The sections 13, while normally energized are termed stopping sections as they function to arrest motion of the train when (lo-energized, while the sections 12 are constantly energized. To illustrate the relation of corresponding parts in each of the block sections under varying conditions I have shown diagrammatically the necessary elements and wiring connections conventionally indicated in the drawing at A, B andC, as well as the semaphore signal of each section, the lower or distant semaphore arm being indicated at 15 and the upper or home semaphore arm at 16. Each block section equipment includes a current converter or frequency controller shown in de tail in Figures II and III, wherein 17 indicates generally a commutator or rotary reversing switch comprising a diskof insulating material and having concentrically applied to its face a pair of collector ringslS and 19, and two annular series 20 and 21 of spaced segments, the segments whereof are arranged in radialqalignment. Each segment of the inner series 20 is connected by means of concealed conductors 22 'withthe two flanking misaligned segments of the outer series ,21, and each segment of said outer series 21 is similarly connected at each end by means of concealed conductors 23 with a pair of misaligned flanking segments of theinner series 20. i

A concealed conductor 18 connects the collector ring 18 with one of the segments in the inner segmental ring 20, while a similar conductor 19 connects the collector ring 19 to another unit of said segmental ring 20;

and it is noteworthy, at this juncture, that the insulated intervals between the segments comprising the rings 20, 21 must be of sufficent gap so that a direct current arc of requisite voltage and amperage will not flow or jump? from segment to segment when the required velocity is attained. The commutator or frequency controller 17 is mounted for rotation upon a shaft 2%, having. a-collar. 25 formed therewith against which the disk bears in tight engagement brought about by pressure of a nut 26 threaded upon said shaft engaging a collar 27 which contacts'withthe rear face of said disk. The shaft 24 isjournaled in bearings 28 and may be provided with a pulley 29, for imparting rotative movement thereto; 0r,;if desired, said shaft may be directly coupled to the shaft of a suitable motor. A pair of spring pressed brushes 30 and 31 are provided, engaging respectively the inner and outer collector rings 18 and 19; and, in similar manner, a pair of brushes 32 and 33 are arranged towipe the face of the commutator disk in radial alignment, so as to respectively engage the segments of the annular series 20 and 21 during rota tion of the disk.. The commutator 17 is driven by means of a direct current motor 34, which-is fed through the lead 35 directly connected thereto, and by means of a lead 36which extends to the brush Sl-that is provided ing to the movable contact of a variable resistance element 38. A branch 39 is taken from the lead 35 and extended to the brush 30. It will, of course, be readily under stood by those acquainted with the art that the direct current-input -fed to the brushes 30, 31 will produce an alternating current-outputat the brushes 32, 33 when the commutator 17 revolves. The brushes 32 and 33 areconnected by means of conductors a0 and 41-respectively-to a live section 12 of the conductor 11 and to one of the track railslO. lhe variable resistance element 38 is in series with a fixed resistance element 42, which in turn is disposed in series with the movable conductor of a second variable resistance element 43, in turn connected through the medium of a conductor id to a contact point 15, forming part of a switch 51 designed to be operated byancl in unison. with the lower arm 15 or with a branch conductor 3'? extend distant semaphore, in any of the wellknown ways, or as indicated by the dotted lead lines connectin said parts. The switch 51 includes a switch arm 56 adapted to oscillate between the contact 45 and an adjoining contact 58. The switch arm 56' is connected by mean of a conductor 49 to the juncture of the variable resistance 38 and the fixed resistance 12, as shown in the drawing. Associated with the home semaphore arm 16 is a switch 50, said switch 50 comprising an arm 52 operative by and in unison with said semaphore arm 16, as before described in reference to the arm 15; and that it is connected by means of a conductor 53 to the live section 12 of a preceding block'considered with reference tothe direction of travel of the train, and a contact 5% which is connected by means of a lead 5:5 to the adjacent stopping section 13. It is here noteworthy that the switches 50 and 51, withv their associated contacts, are in addition to the usual contacts and are operated by the signal or semaphore movements.

It will be apparent that since the main leads 35 and 36 are in constant electrical communication with one of the rails 10 and conductor 12 through the intermediary of the commutator 17 a constant potential will be impressed upon the live rail 10 and conductor 12, and the circuit will be completed by passage of the current through the car wheels and axlesof a passing train. Owing to the provision of the commutator 17 a direct current fed from the leads 35 and 36 is converted into what, for the want of a better term, may be called an alternating current, although differing therefrom in several particulars, as forinsta-nce the absence of a sine curve characteristic, thecurrent flowing in a series of impulses which are constantly reversing and which begin and end with a maximum electromotive force. This is occasioned by reason of the segments of the series 20 and 21 being misalignedly connect ed, or one to 'the other alternately as described above, so that the collector brushes and 33,being stationary and in radial alignment, connect alternately during rotation of the commutator 17 with the inner and outer segments of the two series 20, 21,. thereby constantly reversing the current at a rate of reversal or frequency determined by the speed of rotation of. the commutator 17. The change in speed of rotation of the motor 3 1, and hence the frequency of the converted current is obtained by manipulation of the sen aphore arms 15 and 16, communicated in turn to the switches 50 and 51, by which the interposition of the resistance controlling said motor is accomplished. For instance, observing the relation of the parts at signalling location A which are set to indicate a clear track and to permit passage of a train into the block controlled thereby without diminution of speed, the switch 51 is in a position so that the arm 56 engages the contact 45, thereby establishing a circuit which includes the leads 36 and 37, resistance 38, conductor 4-9, switch arm 56, conductor 44, and conductor which connects the latter with a terminal ofthe motor 34-, the current returning therefrom'through the lead 35. Since this circuit includes only the single re sistance 38, the motor 84 is permitted to rotate at its maximum speed, and hence the converted current will be fed to the rail 10 and conductor 12 at a maximum frequency which acts uponthe mechanism of a locomotive equipment responsive thereto to permit the train to move without diminution of speed. At this point it is to be noted that a train entering any block controlled by my novel system first encounters the portion 12 of the conductor 11, betore rolling onto the minor portion 13; or, in other words said portion 13 is located adjacent the exit end of each block.

The signaling mechanism shown at B is for the purpose of illustrating caution conditions or as effected by diminution of spee'dincident to inclusion in the circuit described in the preceding paragraph of the fixed resistance 12-of the train entering the block controlled thereby.

To further illustrate the operation of the mechanism the parts at C have been shown as set to indicate a danger or stop position for the block controlled thereby or when both semaphore arms 15 and 16 are elevated which results in the shifting of both switch arms of the switches 50 and 51 to the open positions. In this'position of the parts the motor 34 is permitted to run only at a further reduced rate of speed owing to the fact that the current now traverses all of the resistances 38, 1-2 and 43. The converted current under such conditions aii'ects the mechanism of an approaching locomotive in the block controlled thereby, before the danger zone can be reached, inasmuch as the locomotive must traverse a section 13 which, in the present instance, is de-energized by reason of the opening of the switch 52, and as soon as the locomotive passes beyond the live' section 12 of the preceding conductor rail section 12 and rolls onto said de-energized section 13, the mechanism of the locomotive equipmentbeing thereby de-energizedis instantly actuated to apply the air brakes and cause the train to come to an abrupt stop before its inertia carries it beyond said section 18.

Briefly summarizing, and assuming the signal indications areas shown, a train entering a block controlled by signal indications A.or line clear tra.verses the live rail section '12 of said block, which is supplied with current of full speed frequency by virtue of the resistances 43 being the rail section 12 therein receives somewhat reduced frequency current, so that caution speed conditions exist up to the exit from'said block section. Should the train enter a block under C signal, indications, after passing the caution or B controlled block, the switch 56 being open permits both the resistances 4:2 and 43 to become operative to reduce the speed of the corresponding motor 34, so that current at a considerably reduced frequency is fed to the rail section 12 under control of C, while the rail section 13 in said block receives no current at all, or is totally de-energized, due to the switch 52 now being open, and as a result the train is automatically brought to a dead stop before it can pass the exit of the block under coutrolqof C signalling indications.

lVhile the switches 50 and 51 may be controlled manually or by operation of the semaphore arms, it will be apparent that,

if desired, the system may be'rendered fully automatic by providing means of a simple character adapted to beactuated by a passing locomotive to set said switches in a block in advance of the approaching locomotive.

The locomotive equipment to be used in connection with the controlling system described may be: of anextremely simple character, andas one example-l have illus trated a means in Figures IV, V, and VI, adapted to perform the intended functions; In these views, 61 indicates a locomotive axle upon which a bevel gear 62 is fixed for re- ,tative engagement with a gear 63, in turn mounted upon a governor shaft G l, which carries a centrifugal governor mechanism ca adapted upon rotation to impart motion to a rock lever 65. This lever 65 is suitably supported and adapted to actuatethrough the medium of a link 66a bell crank 67 in turn connected by means of a link 68 to one movable member 01 a contact making device 69. This contact making device 69 comprises a series of spring influenced pivotal contacts 70, 71 and 72, which are adapt-- ed to be successively picked-up and engaged by a pivoted contact arm 73, movable also with respect'to the movable contacts 70, 71 and 72. to a link 74 made extensible by having a spring 75 interposed therein, said link 74- being connected to one arm of. a bell crank 76, the other arm of which is connected by means of a link 7 7 to a rock lever 78. The lever 78 is oscillated through the medium of a centrifugal governor mechanism 79, which is operated by means of a bevel gear combination 80, 81, said latter gear 81 being ro- The contact arm 73 is connected I tated by means of a split phase motor 82, 'one terminal of which is grounded to the engine and the other connected to a shoe 83 adapted to travel along the conductor 11 between the track rails 10, 10, The locomotive equipment also includes three relays 84, 85 and 86 adapted to be energized by current supplied from a source 87 and controlled by connections to the contacts 70, 71 and 72-respectivelyof the movable contact maker 69. The relay 84 controls the energization, through the wiring illustrated, of an electromagnet 88, forming part of a mechanism for accomplishing the release of the throttle and which is shown in Figure V. The throttle valve, indicated at 89 is actuated by means of a link 90, carrying a pivoted hook member 91, which normally is interengaged with a similar hook member 92 actuable by the throttle lever 93. As long as the members 91 and 92 are in mutual engagement the steam throttle may be opened and closed by shifting the throttle lever 93, in the, usual manner. The hook member 91 however, is normally urged to a position tending to release the member 92 by virtue of a spring 94 but, contrarily, said hook member 91 is urged towards engaging position by means of a core 95 which, under the influence of the energized electroinagnet 88 tends to retain the hook mem- 'ber 91 in engagement with the hook member 92 by overbalancing the tension of the spring 9 1 It is well to note that the throttle valve 89 being only partially balanced will. automatically close on disengagement of the members 91, 92. Thus it will be clearly seen that the throttle lever 93 would become ineffective until returned to latched engagement with the member 91.

The locomotive equipment also includes means for venting the brake pipe to secure an application of the brakes. To this end a valve, illustrated in FigureVI, is provided and connected to the brake pipe, the valve indicated at 96 being actuated through the medium of a stem 97, having its terminal extended to provide a core 98, which operates axially through two electromagnets 99 and 100. The valve 96 is normally urged to open position by means of a spring 101 interposed between the valve casing and an adjustable abutment 102, threadedly engagedupon the valve stem 97, said valve 96 being held in'closed position against the influence of the spring 101 by the energization, singly or in unison, of the electromagnets 99 and 100. To balance movement of the valve 96 so as to ensure a positive and free brake application, I may append a piston 103 thereto operating in a cavity 104; in the valve casing which is placed in communication with the atmosphere by means of a restricted aperture or vent 105. I

In h perat n of the l c m t ve equ pment, assuming that the engine is traveling at a maximiun rate of speed the contact members 69 and 7 3 will be shifted towards each other, in an obvious manner, by rapid rotation of their respective governor mechanisms to extreme advanced positions, where upon all the tnree contacts 70, 71 and 72 will be successively interengaged with the member 73 contacting the member '72, so as to effect and maintain energization of the associated relays ea, 85 and 86. Thus it will be clear, that, the electromagnet 88 being energized through the normally closed position of its corresponding relay 84 re tains the hook members 91 and 92 in mutuall en a ed position )ermittin ad'ustb a l a ment of the throttle to vary the admission of steam in the usual manner. The electromagnets 99 and being likewise energized function to retain the valve 96 in closed position. Should the train enter .a block controlled by the signal set to caution, as for instance shown at B in Figure 1, and the engineer has not reduced speed, the motor 82 of the locomotive ecuipment will be automatically supplied with a current of a lesser frequency, and as a result thereof its speed of rotation is reduced. The first result of such automatic reduction of speedof the motor 82 is to cause diminution in the speed of rotation of the associated governor mechanism 79, which in turn effects retraction of the contact member 73 to a position wherein the contact 7 O is released, but retaining engagement with the contacts 71 and 72. As a consequence the relay 84: is tie-energized in turn causing de-energization of the electromagnet 88, which effects release ofthe hook member 91, under the tension of the spring 94 thereby causing the throttle valve 89 to automatically move to closed position and shut oii steam from the locomotive cylinders Should the train however proceed until it approaches the end of the block controlled by signal setting 13, with the signal in the block approached set against it, as shown by C, resulting in the formation of a dead section 13, the supply of alternating current to the motor 82 will be automatically discontinued, thus efii'ecting retraction of the contact 73 beyond the contact 71, ole-energizing the relay 86 and its associated electromagnet 99, so that the valve 96 of the brake pipe vent will be shifted under the influence of the spring 101 against the retarding influence of the still energized electromagnet 100 to a position where the brake pipe is slowly vented to effect a service application of the brakes. On the other hand, if the, engineer has properly reduced speed to conform with track side conditions it will be seen that with the foregoing position of the parts, should the locomotive, for any reason pick up speed, even during the service application of the brakes, as'for instance byproceeding onto a 'ClOWD. grade, such increase in speed will be imparted through the governor mechanism to effect still further retraction of the'contact member 69 to the left, resulting in disengagement between the contact 72 and the contact 73. This act claim:

results in the de-energization of the relay 86 and its associated electromagnet 100, thereby permitting the spring 101 to act with full force to move the valve 96 to a full open position quickly venting the brake pipe and causing an emergency application of the brakes. In this manner the speed of the locomotive and the speed of the motor 82 are permitted to act as a check, one upon each other, thereby effecting complete control of the locomotive at any predetermined speed of said motor 82, irrespective of external conditions acting upon the locomotive to advance or retard its speed. Other advantages result from the arrangement described, as for instance, complete control of the speed of the locomotive independent of the control of the engineer, so that the predetermined rates of speed fixed by law may not be exceeded or the train subjected to unwarranted risks-by negligence of the engineer. Owing to the fact that during normal operation the system is constantly energized throughout on closed circuits, any derangement of the mechanism tending to cause a break in the circuits would act to effect a reduction in speedor stoppageof the locomotive, thus increasing the factor of safety. Other advantages will be readily apparent to those familiar with the art to which this invention relates. It has been found by experiment that a split-phase motorsuch as 82-0n the locomotive will operate efficiently on the type of converted current mentioned above, although the splitphase winding must be specially designed to withstand continuous connection to the source of current. In lieu of the particular form of current converter described I may employ an ordinary direct coupled motorgeneiator set to furnish an alternating current. It is understood that the term locomotive as used herein may include also an electric locomotive or other tractive vehicle; and that throttle is the equivalentof a controller or any device for controlling the speed of the vehicle. Also, in place of the centrifugal governors 64 and 79 I may use any other suitable form of speed responsive mechanism, While I have proven by actual service tests that all changes in the speed of the frequency controller or current converter 17, gave a proportional change to the speed of the split-phase induction motor 82 when direct current was supplied to said frequency controller.

From the foregoing description and an examination of the drawings it will be obviprinciple that variation in the frequency'of an alternating electromotive force insures a corresponding variation in the speedof an "induction motor connected thereto.

Having thus described my invention, I

1.1m a train controlling system, including a track equipment having-a conductor paralleling the tracks 1 divided into sections, locomotive equipment including means r sponsi-ve to an alternating current received through the conductor sections in passing thereover toei'l'ect control in'the speedof the locomotive, and a series of trackside equipments, one for each conductor section and each including means for generatingand impressing a pseudoalteri1ating current upon its corresponding section, means for controlling the frequency of the'current impressed with respect to successive track equipments so as to effect reduction in speed of a train passing fromone section "to another by reduction of the frequency of "the current impressed upon the section approached, a deenergizable section interposed in each of the aforementioned conductor :sections, \and means controlling said "de-energizable or dead section, whereby, the locomotive equipment is'rendered responsive in passing over paralleling the tracks, said conductor being divided into live sections Withastopping or de-energizable 560131011 for each such dead section to effect a complete stop block, a locomotive equipment .including means responsive to an alternating current received from the conductor sections to effectwcontrol of the speed of the locomotive, and 'filwlTIiLCk equipment including a plurality of signal stations, one for each conductor sectionto impress a pseudo-alternating currentithereupon and to vary the frequency ofthe current impressed vto effect control of the speedof the locomotive," and means for connecting and disconnecting each stopplng section with an associated live conductor section to permit control of the'locomotive in ,passing over a stepping section when the latter is energized, and to effects. responsive action of the locomotive equipment Whenpassing over such stopping section when the latter is desenergized to-automatically effect stoppage of'the locomotive.

3. Ina train controlling system, including a locomotive equipment having means responsive to [an alternating current to eff fect' a'secondary control of the speed of the locomotive, a'track side equipment including" a current converter forconvertingra direct current. into an alternating current. and for impressing the same upon the responsive 6 I 1,727,ao7

means of the traveling locomotive and. means for varyingthe speed of the converter to vary the frequecy of the current impressed.

4. In a train controlling system, a locomotive equipment including means responsive to an alternating current of varying frequency to effect a secondary control of In testimony whereof, I have hereunto si ;ned my name at Easton, Pennsylvania, .tlns 13th day of March, 1926.

FREDERICK A. NIXON.

bination in a locomotive With the throttle operable by initial reduction in speed of the motor to close the throttle, and means operable by a secondary reduction in speedof the motor to actuate the brake valve to effect I an application of the brakes.

6. Ina train controlling system, a locomotive equipment including a split-phase motor to receive alternating current from an external source, a multicontact circuit maker, means controlled by the circuit maker to actuate controlling devices of the locomotive, and means controllable by changes in speed of: the locomotive acting upon the circuit maker in opposition to the controlling effect of the motor to effect adustment of the circuit maker to vpositions reverse to those effected by the motor, for the purpose set forth.

7. In a train controlling system, a loco- "and brake valve, of a split-phase motor for receiving alternating current of variable frequency from an external source, means motive equipment'including a split-phase" motor responsive to alternating current received from an exterior controlling source, a

governor mechanism operable by the motor, a circult controller operable by the governism operatively connected to the Wheels of nor mechanism, a second governor mechathe locomotive to effect adjustiverelation of the circuit controller to positions reverse to those eflected by the first governor mechanism, and means operable by the circuit controller to actuate the locomotive con trolling devices.

8. In a train controlling device, the com bination in a locomotive of a throttle valve having aseparable operating devlce, means urging the operating device to separation .to permit release of thethrottle valve, and

normally energized means retaining thedevice in interengaged relation, and means responsive to exterior control-to .de-energize the retaining .means forthe purpose set forth. 

